The use of shaving aids on razor blades to provide lubrication benefits during the shave is known. See e.g., U.S. Pat. Nos. 7,121,754; 6,298,558; 5,711,076; 5,134,775; 6,301,785 and U.S. Patent Publ. Nos. 2009/0223057, 2006/0225285. The use of certain cooling sensates in shaving aids has also been disclosed. See e.g., U.S. Patent Pubs. 2007/0077331, 2008/031166, 2008/0300314A1; U.S. Pat. Nos. 5,451,404, and 7,482,373; and WO2007/036814A2. For example, it has been described that cooling agents and/or essential oils can be included in the shaving aid to deliver a fresh and cool feel after contact. It has been reported, however, that a substantial amount of the essential oil can be lost due to volatilization prior to use. See U.S. Pat. No. 5,095,619. U.S. Pat. No. 5,713,131 attempts to fix this potential problem by introducing non-volatile cooling agents into the shave aid, such as non-volatile menthol analogs. Examples of other shave aids containing menthol and other actives are disclosed in U.S. Pat. Nos. 5,095,619, 6,298,558, 6,944,952, and 6,295,733. See also, U.S. Pat. No. 5,653,971 (disclosing a shaving aid which includes an improved shaving aid composite (or lubricating strip) which contains an inclusion complex of a skin soothing agent, such as menthol, with a cyclodextrin) and, U.S. Pat. No. 5,713,131 (disclosing a non-volatile cooling agent, such as Cooling Agent 10, WS-3, WS-23, Frescolat ML, Frescolat MGA and Menglytate). It has been reported that these shaving aids deliver cooling agent during use.
Many ingredients that are normally used in skin care, however, are not easy to use in a conventional extruded shaving aid. This is because many shaving aids are extruded through a die or otherwise processed at high temperatures, such as from about 160° C. to about 180° C. Formulating extruded shaving aids with cooling agents is challenging since many of these cooling agents have boiling points below the typical shaving aid extrusion temperature. Furthermore, extrusion subjects the shaving aid compositions to high pressure which can also add to the degradation of the cooling agents. One commonly used cooling agent is L-menthol. The addition of this cooling agent as a neat ingredient in a shaving aid has been described but the cooling affect is believed to be limited by the concentration of L-menthol used and lack of shelf life due to its high volatility. Cooling agents having greater cooling intensity are known but they tend to have even lower evaporating temperatures making them less likely to be suitable for the high temperatures and pressures used in conventional shaving aid extrusion.
Various cooling technologies have also been described in cosmetic and/or oral care formulations. See e.g. U.S. Patent Pub. Nos 2009/0311206 and 2009/0306152, both assigned to Beiersdorf, 2006/0276667, 2010/0086498, 2010/0086498, 2011/0081303, and 2011/0082204. Not all cooling technologies however are suitable for processing in normal shaving aid making conditions. In particular, some cooling technologies are believed to be so volatile that they can be lost during the shaving aid making process or otherwise become less active such that they are not perceivable during use. As such, there is a need for technologies which can survive the skin engaging shaving aid member making process while maintaining sufficient molecular activity to provide meaningful or long lasting cooling benefit.